THEORY OF STRUCTURES 1CE131P SY 2015-2016ENGR. HARVEY A. MALOLOS
LOADS ON STRUCTURES
OBJECTIVE•To design a structure that will be able to withstand all the loads to which it is subjected while serving its intended purpose throughout its intended life span
REFERENCE•National Structural Code of the Philippines, Vol.1 Sixth Edition(NSCP 2010)
LOAD TYPES•Dead Load•Live Load•Environmental Load
DEAD LOAD•Dead Loads are gravity loads of constant magnitude and fixed positions that act permanently on the structure•Consists of the weights of the structural system itself and all other material and equipment permanently attached to the structural system
DEAD LOAD•NSCP Table 204-1MINIMUM DENSITIES FOR DESIGN LOADS FROM MATERIALS (kN/m3)Aluminum-26.7Concrete, Reinforced-23.6Glass-25.1Steel, cold drawn-77.3Water-9.81
DEAD LOAD•NSCP Table 204-2MINIMUM DESIGN DEAD LOADS FOR CEILINGS (kPa)Acoustical Fiber Board-0.05Gypsum Board (per mm thk)-0.008Mechanical duct allowance-0.20Suspended steel channel system-0.10
DEAD LOAD•NSCP Table 204-2MINIMUM DESIGN DEAD LOADS FOR FLOOR FINISHES (kPa)Cement finish (25mm) on stone-concrete fill-1.53Ceramic or quarry tile (20mm) on 13mm mortar bed -0.77Hardwood flooring, 22mm-0.19Linoleum or asphalt tile, 6mm-0.05
SAMPLE PROBLEM (DEAD LOAD)•The floor system of a building consists of a 15-cm thick reinforced concrete slab resting on four steel floor beams, which in turn are supported by two steel girders. The cross sectional areas of the floor beams and the girders are 94.8 cm2and 337.4 cm2, respectively. Determine the dead loads acting on the beam CG and DH and the girder AD.
LIVE LOAD•Live Loads are loads of varying magnitudes and/or position caused by the use of the structure•Magnitude of design live loads are usually specified in building codes
LIVE LOAD•NSCP Table 205-1MINIMUM UNIFORM LIVE LOADS (kPa)Residential, Basic floor area-1.9Armories-7.2Exit facilities-4.8Offices-2.4Stores, Wholesale-6.0
IMPACT•When live loads are applied rapidly to a structure, they cause larger stresses than applied gradually•To account for the increase in stress due to impact, live loads are increased by certain percentages
IMPACT•NSCP Section 206.3.1 ElevatorsAll elevator loads shall be increased by 100% for impact.
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- Summer '16
- prof harvey
- Structural Engineering, Dead and live loads, Structural load, Kzt